Many lay people and even some health professionals recommend mayonnaise to treat head lice. Lots of parents swear by it. It’s been a popular home remedy for decades - and it wouldn’t have stood the test of time if there weren’t something to it.
These parents prefer mayo to standard lice treatments because they (rightly) don’t want to put toxic pesticides on their children’s heads … and because hair treated with mayonnaise will be soft and shiny when the treatment is all over.
The idea is that mayonnaise suffocates the live lice. It doesn’t affect the eggs, though … they’re well protected in their nits. So you must comb out all the nits with a good lice comb after attacking the live lice with the mayonnaise. Otherwise the nits will hatch in a few days, and you’ll be right back where you started.
Some suggest that it’s possible to avoid combing altogether, by treating with mayonnaise every four days for two weeks. In this scenario, the mayo would kill all the live lice on a person’s head at the time of each treatment. You would basically be waiting for each batch of eggs to hatch out of their nits, and then killing them with mayonnaise. There’s a problem with this theory, though. Read on.
Researchers have asserted that mayonnaise and other suffocating agents don’t really kill the lice. The lice appear dead but have really just entered a dormant state due to lack of oxygen. Some or all of them will recover eventually.
If these researchers are right, then the mayonnaise treatment will make the live lice much easier to comb out. Basically it will stun them for a few hours. But to get rid of them forever, the combing-out process is still crucial.
First, saturate the hair, from scalp to ends, with mayonnaise. Pay special attention to the entire scalp and roots of the hair, because that’s where the lice prefer to hang out and where they lay their eggs. This can take a LOT of mayonnaise, depending on how long and thick the hair is.
Recommendations vary on how long to leave the mayonnaise in the hair. Some people leave it in only two hours. The Fisher-Price website recommends over 12 hours. Dr. Greene, a noted pediatrician, recommends at least 8 hours. Presumably, the longer you leave it on, the more effective it will be. If you’re leaving the mayonnaise in for a long time, you can apply it right before bed and leave it in overnight.
Make sure to use a very tight-fitting shower cap, or even better a swimming cap. Do NOT use plastic wrap or a plastic bag. These items are very dangerous, and you must never put them on a child’s head.
Don’t use the overnight treatment on a very young child, or on any older child who might possibly take some strands of hair out of the cap and chew on them or suck on them. The mayonnaise will turn rancid after a few hours, and once it’s rancid, the mayonnaise itself is not safe to consume!
There are some downsides to using mayonnaise to treat head lice.
Some people love the smell of mayonnaise. Other people can’t stand it. If you want to try mayo, make sure you know which category the people in your home fall into, and what they are willing to tolerate, before you start.
Mayonnaise may not be easy to wash out of a child’s hair. Dishwashing liquid will work better than regular shampoo. After removing the mayo, you can rinse with white vinegar to make the nit-combing easier. (Some researchers have recently confirmed that vinegar does loosen nit glue.)
My recommendation for treating head lice on a child over five is to go with a good enzyme shampoo. The enzymes dissolve the exoskeletons of the live lice, killing them. The enzymes also loosen the nit glue so that nits come out of the hair much more easily.
A big difference is, you leave the enzyme shampoo on the hair and scalp for ten minutes rather than overnight. And it’s easy to get out of your hair. So I think an enzyme shampoo is a better (though more expensive) choice than mayonnaise to treat head lice.
Head lice can be removed safely and successfully. Just stay calm, follow through, make sure all lice and viable nits are gone.